This invention relates in general to the development of film and more particularly to a system and method of digital film development using visible light.
During conventional chemical film processing, several different solutions are normally applied throughout the development process in order to produce a negative. Developer is applied to expose film to convert exposed silver halides into elemental silver. The by-product of this reaction reacts with couplers in order to create color dyes within the film. The reaction is stopped by a stopping solution. Any unreacted silver halides and the elemental silver present in the film layers is washed out of the film. The completed negative includes separate emulsion layers composed of color dyes.
Conventional scanner systems generally digitize film using visible light to detect and measure the colors associated with the color dyes in the negative. Conventional scanner systems require that the silver halide and elemental silver particles be washed from the film. The elemental silver particles will block, or occlude, the light and cause speckling used to detect and measure the dye clouds in the negative.
In digital film development, after the application of developer, the developing film is scanned at certain time intervals using infrared light so as not to fog the developing film. Color is derived from the silver latent image detected during development by taking advantage of the milkish opacity of the elemental silver to optically separate the individual layers. Once separate optical data is identified for each layer of emulsion, optical data associated with each layer of blue, green, and red emulsion is used to digitally create a color image.
Conventional digital film processing systems utilize infrared light in order to avoid fogging the film as it develops. In particular, each layer of the developing film remains photosensitive to visible light during the digital film process. The film is not substantially photosensitive to infrared light, which allows the silver latent image to be scanned at multiple development intervals.
One advantage usually associated with digital film development is the ability to develop film using a single application of developer. Digital film development does not require, for example, the stop, fix, clear, wash, wetting agent, and dry processing steps, nor the additional developer or other chemical solutions, used in chemical film processing. As digital film development primarily uses infrared light to detect the level of exposure of silver halides, the presence of elemental silver during such processing may inhibit accurate detection of images represented on the blue, green, and red layers of film emulsion similar to other defects such as scratches and other abnormalities. This problem may be particularly pronounced in detecting latent images held in the green layer of the film emulsion that is generally more difficult to discern relative to latent images held in the upper blue layer and lower red layer of film emulsion.
In accordance with the present invention, a system and method for digital film development using visible light is provided that substantially eliminates or reduces disadvantages and problems associated with previously developed systems and methods. In particular, the system and method for digital film development using visible light allows for the reduction of disadvantages during film processing that are associated with the presence of elemental silver.
In one embodiment of the present invention, a system for the development of a film is provided that includes an infrared light source and a visible light source. The system also includes at least one sensor operable to collect a first set of optical data from light associated with the infrared light source and a second set of optical data from light associated with the visible light source. The system further includes a processor in communication with the at least one sensor, the processor operable to determine an image on the film in response to the first and second sets of optical data.
In a second embodiment of the present invention, a method of digital film development is presented that includes comparing a first set of optical data collected during a transmission of infrared light through a film with a second set of optical data collected during a transmission of visible light through the film.
Technical advantages of the present invention include providing a system and method for digital film development using visible light that reduces disadvantages and problems associated with previously developed systems and methods. In particular, various embodiments of the present invention allow undesirable data introduced by the presence of elemental silver to be removed or filtered. Additionally, various embodiments of the present invention present higher quality digital images by eliminating defects caused by the presence of elemental silver. A further advantage of various embodiments of the present invention is that more detailed image production is accomplished without the need for additional developers or other chemical solutions.
Other technical advantages will be readily apparent to one skilled in the art from the following figures, description, and claims.